The truth about waiting for a drop is that someone who is waiting for a price drop in Bitcoin will never be satisfied. Even if the person is lucky and the drop happens, they may still want another drop which may not happen and it becomes a missed opportunity. So, anyone who is still waiting for Bitcoin to dip before starting to invest is just fooling themselves and may regret it in the future because bitcoin is unpredictable and that reason why at any price bitcoin is it is a great opportunity to buy.
If anyone hasn't had any positions in Bitcoin, I think they should buy with 25% of the portfolio now and then buy more on every dip. This is because in case the price pumps from here and doesn't give a pullback, the person won't be left waiting. Also, I would not feel nervous buying near 110K because I know that this is not the ultimate top for this cycle and for years to come, it is like buying under 50K 
I completely agree, Bitcoin is the safest and most reliable investment out there. For me, I split my portfolio into three parts based on risk: low, medium, and high. Bitcoin is definitely my low risk asset and the main part of what I hold. I keep buying it and will keep accumulating (I’m still new to accumulation) and don’t plan to sell anytime soon. Then, I put about 10 to 20% maximum into medium and high risk stuff like shitcoins not because I fully trust them, but because they might give big gains in a bull run. I always manage it carefully within my risk limits. To avoid making the same mistakes older crypto pals made, I prefer staying on the safer side.